Feed frame



June 20, 19567 L. H. AUSTIN 3,326,145

FEED FRAME Filed May 28, 1965 www;

RNEY

United States Patent() 3,326,145 FEED FRAME Leonard H. Austin, 2857 Faber Terrace, Far Rockaway, N.Y. 11691 Filed May 28, 1965, Ser. No. 459,734 9 Claims. (Cl. 107-17) This invention relates to new and useful improvements in a powder feeding device and more particularly seeks to provide a tablet feed frame for directing tablet powders into the die openings of a rotating table.

Various devices have been devised for feeding powdered m-aterials to a movable member during manufacturing processes. In general these devices have Vhad the objective of high speed feeding, minimum waste and minimum machine maintenance. In the tabletting art, feed frames which are desirably spaced 1/1000 of an inch above `a rotating table are subject to (1) excessive wear, (2) discoloration (contamination) of the powder where rubbed between the frame and table, (3) excessive loss of expensive material through the space and a combination of these three, depending upon the specific spacing, speed of operation, age of elements, etc.

Therefore, it is an object of the present invention to provide a new and improved feed frame for feeding powdered materials.

It is another object to provide a feed frame for use with a rotating feed table, which frame has means contacting the table to retain powdered materials therein.

It is an additional object to provide a feed frame having compartments with means for varying the flow rate of materials between compartments.

It is a further object of the present invention to provide a feed frame for use in conjunction with a rotating feed table, which frame -has means for minimizing the wear of the frame and table and yet preventing contamination of the feed materials.

I have found that a resilient soft web, for example a plastic such as nylon, polyvinylchloride, polypropylene, polyethylene and polytetrailuoroethylene, may be inserted into the bottom surfaces of a feed frame (or comprise the entire feed frame) so as to contact t-he rotating table and thus retain the tabletting material within the compartments and by the same means preventing wear t-o the feed frame and rotating table. In addition, the web may be selectively moved laterally into the openings between compartments to vary the flow rate to compensate for the variable flow rates of different materials. The web may be resiliently biased into contact with the table to automatically compensate for wear of the contacting surfaces of the web and table.

With the above objects and features .in View, the nalture of which will be more apparent, the inventionl will be more fully understood by reference to the accompanying drawings, the detailed description and the appended claims.

In the drawings:

FIG. l is a fragmentary schematic view of a tableletting machine with a feed frame constructed in aocordance with this invention;

FIG. 2 is a top plan view of ya rotary feed table having die cavities and a feed frame mounted thereabove;

FIG. 3 is a bottom plan view of one compartment only of the feed frame showing a web mounted in the bottom surfaces;

FIG. 4 is an enlarged sectional view of the feed frame taken along line 4 4 of FIG. 2 particularly illustrating the manner in which a web is inserted in a slot in the frame;

FIG. 5 is a partially sectioned view of a portion of a feed frame wall illustrating the manner in which a Patented June 20, 1967 spring 'biased web is inserted in a slot in the wall; and

FIG. 6 is -a partially sectioned view of a portion of a frame wall illustrating the manner in which a slotted web is inserted in a slot in the wall.

The machine as described specifically herein is a Model B-2 Rotary Tablet Machine manufactured by F. I. Stokes Machine Company, Philadelphia, Pennsylvania, but the invention is obviously applicable to any such machine. These machines are always provided with a feed frame having a series Iof compartments defined by walls for entrapping materials to be fed into die cavities. The compartments are separated by walls with an opening therethrough for flow of the tabletting material. In normal use, the feed frame is xed above a rotating feed table having die cavities therein. The powders are fed into one compartment Aand carried by the rotating table into the other compartments. The die cavities pass beneath the compartments and in this manner are filled.

As shown in FIG. 1, machine 10 includes a rotary feed table 11 which is mounted on a shaft 12 for rota- -tion therewith. Shaft 12 is in turn rotatably supported in a closely fitting cylindrical bore 13 in a base 14. A spur gear 16 is mounted on shaft 12 and meshes with another spur gear 17 supported by a shaft 18 of an electric motor .19. As can readily be seen, energization of motor -19 will rotate table 11 through the gears and shaft 12.

Rotary table 11 includes cylindrical apertures 21 (FIG. 2) which serve as die cavities for shaping tablets from powdered materials. An upper punch 22 and a lower punch 23 -are shown in FIG. 1 which may be moved up -and down inI the directions of the arrows. The specific `apparatus for moving the punches up and down is not shown since it does not form a part of this invention and is well known to this art.

. -Referring t-o la die cavity 24 shown dotted in FIG. 1, first punph 23 moves up into the die cavity to close up the lower end. Next, powder is fed into the cavity until it is full and then punch 22 moves downward into the cavity a predetermined distance thus pressing and shaping the powder into a tablet. Subsequently both punches are removed from the cavity and the tablet is ejected in any one of many known ways. For example, the lower punch 23 may push the tablet out of the top of cavity 24.

A feed frame 26 (FIG. 2) includes a series of bottomless compartments 27-30. Adjacent compartments 27 and 28 are separatedby a w-all 32. In a similar manner, compartments 28 and 29 and 29 and 30 are separated by walls 33 and 34,. respectively. Walls 32 through 34 each include apertures 36-38 interconnecting adjacent compartments. Front `wall 41 bounding compartment 30 may include an aperture 42 for permitting substances to flow through onto table 11.

Referring to FIG. 3, a bottom view of compartment 27 is Shown. A pair of webs 44 and 45 are inserted into side walls 47 and 48 which dene the lateral extent of all the compartments. Webs 51 and 52 are inserted into end wall 32 -and stop adjacent aperture 36. Similarly webs are included in walls 33 and 34 which are not shown.

FIG. 4 illustrates the manner in which the webs are inserted into the feed frame. Side walls 47 and 48 include Slots 54 and 55 into which webs 44 and 45 are inserted with a force t to be secured therein. Of course, mechanical fasteners such as screws may be utilized to hold the webs in the slots. Also, wall 32 includes a slot 56 for holding webs 51 and 52. The other walls not shown in FIG. 4 are slotted in an identical manner. All of the webs may be formed from any resilient, flexible, non-abrasive material such as nylon, other plastics, felt, etc. with nylon being preferred. In addition, the entire feed frame may be formed from any of these materials,

it being essential only that the frame lip contacting said table be of the soft material.

As viewed in FIGS. l and 2, the feed frame 26 is positioned above table 11 with the webs in contact with the table. The feed fra-me is supported in a fixed nonrotating position 'by brackets (not shown) which attach to brackets 58 which extend from the sides of the frame. A hopper 60 (FIG. l) feeds the powders into compartment 27. Rotation of table 11 clockwise as seen in FIG. 2 will carry the powder in the direction of walls 32-34. Of course, the powder will pile up against wall 32 and some will be carried through aperture 36 into compartment 28 and in a similar manner through apertures 37 and 38. As table 11 rotates, die cavities 21 pass under apertures 36-38 and become filled with powder. Walls 32-34 slope toward apertures 36-38 and thereby direct the powders toward the apertures. The powders are pre- -vented from escaping from the compartments onto the table by the webs which are in cont-act with the table.

As table 11 rotates, punches 22 and 23 as previously described move in a timed relationship to the rotation of the table to form tablets in the die cavities. Aperture 42 is provided to allow the powder to p-ass from the feed frame onto table 11 so as to keep compartment 30 from overowing. With proper positioning of aperture 42, powder entering onto table 11 will be returned to compartment 27.

Various materials have different flow properties, and one way to compensate therefor is to selectively position the webs in the apertures, for example web 51 into aperture 36 (FIG. 4), thereby effectively opening and closing the apertures in the walls intermediate adjacent compartments.

As seen in FIG. 5, a web `62 is positioned within a slot 63 in a wall `64. Web 62 has a spring 65 with an eye loop 66 formed thereon embedded in the web. Spring 65 may be secured within the slot with a screw 67 extending through the eye loop and into the walls of the slot. This type of an arrangement may be used as an alternative to the web as just described in order to compensate automatically for the irregularities in the surface of table 11 and wear.

Referring to FIG. 6, a web 72 is shown supported in a slot 73 in a wall 74 in a manner identical 'to that described in FIG. 4. However, web 72 is provided with a series of slots 75 which give the web added spring-like resiliency, thereby enabling the web to better adjust for irregularities in the table and wear.

I claim:

1. In a powder feeding machine wherein is provided a circular metal table rotatable about a vertical axis and having a plurality of die cavities disposed along the path of a circle concentric with said axis, -and a xed generally arcuate feed frame spaced immediately above the upper surface of said table with its longitudinal axis overlying the path of travel of said die cavities, said frame including a pair of side walls and a plurality of transverse walls extending therebetween, said side and transverse walls together defining a series of powder confining compartments extending along the longitudinal axis of said frame and said transverse walls being provided with apertures providing communication from one compartment to another; the improvement in combination therewith of a feed frame extension defined by a detachable web extending downwardly from the side and transverse walls of said feed frame into contact with the upper surface of said table and -being formed from a material softer than the material thereof, the web extensions of said transverse walls being relieved in the areasof the apertures thereof to maintain communication between said compartments.

2. The machine of claim 1 in which said detachable web is resiliently biased into contact with said table.

3. The machine of claim 1 in which the bottom of said feed frame is provided with a web-receiving channel and in which the upper portion of said web is received therein for vertical sliding motion with respect thereto.

4. The machine of claim 3 in which means are provided for resiliently biasing said web downwardly into contact with said table.

5. The machine yof claim 3 in which said web is spring mounted within said channel.

`6. The machine of claim 4 in which said biasing means comprise a plurality of angularly disposed fingers formed along the upper edge portion of said web and integral therewith.

7. The machine of claim 4 in which said web is formed from a plastic.

8. The -machine of claim 7 in which said plastic is nylon.

9. A metal feed frame adapted for Iixed mounting -above a movable metal table and including side and transverse walls defining a series of compartments extending along its longitudinal axis, said transverse walls being provided with apertures providing communication from one 4compartment to another, the bottom of said side and transverse walls being provided with a web-receiving channel, a feed frame extension web `mounted within said channel and having its lower edge portion extending below the bottom of said walls, said web being relieved in the areas of said apertures to maintain communication between said compartments, said web being formed from a -m-aterial softer than that of said table, and means for resiliently biasing said web in a direction away from said frame.

References Cited UNITED STATES PATENTS 2,944,493 7/1960 Bailey et al 107-17 2,970,554 2/1961 Haupt 107-17 3,241,656 3/1966 Thornton 198--209 EVON C. BLUNK, Primary Examiner.

SAMUEL F. COLEMAN, Examiner.

A. C. HODGSON, Assistant Examiner, 

1. IN A POWDER FEEDING MACHINE WHEREIN IS PROVIDED A CIRCULAR METAL TABLE ROTATABLE ABOUT A VERTICAL AXIS AND HAVING A PLURALITY OF DIE CAVITIES DISPOSED ALONG THE PATH OF A CIRCLE CONCENTRIC WITH SAID AXIS, AND A FIXED GENERALLY ARCUATE FEED FRAME SPACED IMMEDIATELY ABOVE THE UPPER SURFACE OF SAID TABLE WITH ITS LONGITUDINAL AXIS OVERLYING THE PATH OF TRAVEL OF SAID DIE CAVITIES, SAID FRAME INCLUDING A PAIR OF SIDE WALLS AND A PLURALITY OF TRANSVERSE WALLS EXTENDING THEREBETWEEN, SAID SIDE AND TRANSVERSE WALLS TOGETHER DEFINING A SERIES OF POWDER CONFINING COMPARTMENTS EXTENDING ALONG THE LONGITUDINAL AXIS OF SAID FRAME AND SAID TRANSVERSE WALLS BEING PROVIDED WITH APERTURES PROVIDING COMMUNICATION FROM ONE COMPARTMENT TO ANOTHER; THE IMPROVEMENT IN COMBINATION THEREWITH OF A FEED FRAME EXTENSION DEFINED BY A DETACHABLE WEB EXTENDING DOWNWARDLY FROM THE SIDE AND TRANSVERSE WALLS OF SAID FEED FRAME INTO CONTACT WITH THE UPPER SURFACE OF SAID TABLE AND BEING FORMED FROM A MATERIAL SOFTER THAN THE MATERIAL THEREOF, THE WEB EXTENSIONS OF SAID TRANSVERSE WALLS BEING RELIEVED IN THE AREAS OF THE APERTURES THEREOF TO MAINTAIN COMMUNICATION BETWEEN SAID COMPARTMENTS. 